1. Field of the Invention
The present invention relates generally to integrated circuits, and more specifically, the present invention relates to integrated circuits that are controllers for switching power supplies.
2. Background Information
It is well known that the use of integrated circuits to replace discrete components in electronic circuits can reduce the cost and size of electronic systems. The use of integrated circuits also reduces the power required to operate those systems. A category of electronic systems that benefits from the use of integrated circuits is electronic power supplies. The parameters of cost, size, and power consumption are especially important in application of these systems. Switching power supplies are of particular interest to designers of electronic systems because the highest performance is generally achieved with switching power supply technology.
To realize the goals of systems designers, integrated circuits for switching power supplies should have options that allow them to be used in a variety of different applications. The integrated circuits should require as few discrete components as possible, and they should consume the lowest possible power in operation. An example of a desirable option is the ability to select different switching frequencies so that an optimal design can be achieved for different applications of a single integrated circuit. The package of the integrated circuit should also have as few terminals as possible to minimize cost.